Sliding units are known, essentially consisting of shaped guides or slides of casehardened and hardened alloy steel. The treatments of such sliding units is carried out in a particularly careful way, in order to preserve a high degree of straightness, independently from the length and the section thereof.
Such slides or guides slide or are slidable on suitable supporting devices comprising bearings, mounted on supporting plates, coupled to each other, so as to define complementary seats suitable to accomodate such slides.
In view of such a purpose, the surface of the outer ring of said bearings is beveled on at least one side, and defines, together with an opposite surface of the coupled bearing, said sliding seat. Shaped guides so made are however very heavy, and they require a high treatment and processing precision. They are manufactured in the form of short bars, positioned close to each other, so as to define sliding ways having a determined length.
The so-made supports and related bearings do not allow a high coupling precision and such a strength to be achieved, as to guarantee the desired sliding safety.